Finger-printing apple varieties

SOMERSET cider-maker Thatchers, which has more than 500 acres of orchards and the largest and most diverse collection of apples used in cider making, is working with the University of Bristol on a project using DNA fingerprinting techniques to identify apple tree varieties.

With many old and heritage varieties of apple trees beginning to disappear, the project is using genotyping – a process that compares DNA to find the differences in genetic make-up – to identify different varieties of cider apples.

Led by Professor Keith Edwards from the School of Biological Sciences and post-graduate student Alex Graham, scientists from the university visited Thatchers’ Exhibition Orchard to gather leaf samples for genotyping and identification. The Exhibition Orchard contains hundreds of different varieties of apple tree, many of which were saved from the Long Ashton Research Station in Bristol when cider research stopped in 1985. The researchers have also been out to other Thatchers’ orchards to gather samples, helping them create the largest database of apple tree fingerprints in the world, with over 2,500 genotypes present.

Chris Muntz-Torres, Thatchers farm manager, who has been involved in the project since its inception, says: “As with any research, you’re not always sure what’s going to be found. Although we think we know about the trees in our Exhibition Orchard with detailed plans we’ve compiled over the years as new trees have been planted, you never know, the research may identify a variety that’s been lost and now rediscovered. That would be such an exciting find!”

Professor Edwards says: “By taking a leaf and fingerprinting it, we are in effect creating a barcode for that tree. And from that we are able to produce a reliable process for easy identification in the future.

“By visiting the UK’s most influential orchards, such as at Brogdale, The National Botanic Garden of Wales, and the Thatchers Exhibition Orchard, we’re creating a database that will be a valuable resource like no other for all cider makers.”